This invention relates to a novel formulation and application of a blend of various isomers of Vitamin E, including synthetic Vitamin E, natural Vitamin E, mixed tocopherols, and tocotrienol isomers for synergistic and enhanced antioxidant capacity.
Vitamin E is commonly found in vegetation and more abundantly in seeds from which tocopherols, in the natural state, are easily absorbed and utilized in humans and animals, wild and domestic. Nutritional supplements of natural or synthetic Vitamin E normally are administered by injection or orally. Tocopherols tend to be unstable molecules so to provide tocopherol with a reasonable shelf life, tocopherols are normally supplied with an acetate or succinate group, making Vitamin E acetate or succinate (d- or dl-xcex1-tocopheryl acetate or succinate). These modifications decrease the bioavailability of tocopherol and therefore increase the cost of maintaining a desirable level of Vitamin E in the cells of a body, so that it can provide protection against cell component oxidation. In some species, both the xcex1-tocopherol and xcex1-tocopheryl acetate even in water dispersible forms are not bioavailable.
Enhanced absorption of Vitamin E acetate has been studied previously by using aqueous dispersions and solubilized preparations. It is well known that the efficacy of the hydrophilic nature of aqueous Vitamin E solutions and dispersions upon internal absorption of Vitamin E can be demonstrated by increased absorption of hydrophilic Vitamin E by the normal and compromised intestine. It is known in the art that the source of Vitamin E, natural or synthetic, also affects its bioavailability. The beneficial effects of tocotrienols include cholesterol lowering, antioxidant activity, tumor suppressive effect and inhibition of blood platelet aggregation.
The advantage of administering Vitamin E in a water-dispersible formulation was shown by Bateman et al. (J. Pharm. Pharmacol., 1984, 37(7), 461-464) in a human clinical study in which Vitamins A, E, and B.sub.2 were formulated into a liquid vehicle (Aqua Biosorb) and encapsulated into soft gelatin capsules, which were given orally.
Brooks describes in U.S. Pat. No. 3,253,992 the composition of anhydrous water dispersible fat soluble vitamin preparations and aqueous dispersions of these preparations.
Stillman in U.S. Pat. No. 4,551,332 teaches the use of frozen solutions of Vitamin E blends comprised of glyceryl mono- and distearate and in some cases Jojoba oil for dermatological and cosmetic applications.
Greene, et al. in U.S. Pat. No. 5,179,122 teaches a composition for an aqueous dispersible, free-flowing solid with enhanced bioabsorption and easy handling is a lipid melt blend comprised of a lipid soluble melt blended Vitamin E as the active ingredient and surface active agents to correct the hydrophilic/lipophilic balance (HLB). Vitamin E blend and surface active agents both comprise the melt blend which is absorbed onto an inert carrier to absorb the melt blend.
In fact, Vitamin E is a generic name for a family of four isomers of tocopherols and four isomers of tocotrienols. All 8 isomers have a 6-chromanol ring structure and a side chain. There are 4 tocopherols (xcex1, xcex3, xcex2, and xcex4) with a fully saturated side chain. The 4 tocotrienols (xcex1, xcex3, xcex2, and xcex4), although structurally similar to tocopherols, have unsaturated side chains with double bonds at the 3xe2x80x2, 7xe2x80x2, and 11xe2x80x2 positions in the side chain. Individual tocopherols and tocotrienols differ from each other in the number and position of methyl groups in the aromatic chromanol ring. All isomers of Vitamin E exert a wide spectrum physiological effect. For example in addition to being antioxidants, tocotrienols have been shown to be potent suppressers of B16 melanoma cell proliferation in vitro, and xcex3-tocotrienol has been shown to inhibit the growth of human breast cancer cell growth in vitro more effectively than the popular breast cancer drug, Tamoxifen.
The Vitamin E isomers are light yellow oils at room temperature and are fairly stable to heat and acid, and degrade with alkaline conditions, when exposed to ultra violet light, and when exposed to the oxygen in air. However, recently, the term Vitamin E has become synonymous with only xcex1-tocopherol and therefore, most retail Vitamin E supplements contain predominantly xcex1-tocopherol.
Vitamins are grouped on the basis of solubility in water or oil (fat). As aforesaid, fat-soluble vitamins, like Vitamin E, are found in foods associated with lipids and are absorbed from the intestine with dietary fats. Therefore, Vitamin E intake is recommended with a meal, and normally 20 to 40% of the ingested Vitamin E prepared and delivered in accordance with the prior art, is absorbed. Foods that are rich in Vitamin E include dark green vegetables, eggs, fish, nuts, organ meats, soy beans, vegetable oils, wheat germ, and whole-grain products. However, foods are commonly depleted of Vitamin E due to processing, refining and storage. After absorption in the intestine, Vitamin E is transported to the blood circulation by lipoproteins. As a fat-soluble vitamin, Vitamin E is amenable for entry and storage in cell membranes.
The hallmark of Vitamin E isomers is their sacrificial antioxidant property due to the ease with which oxidation occurs in Vitamin E isomers with respect to other molecules in the body. Vitamin E is the primary defense against cell membrane and DNA damage and protects LDL and other lipid-rich biochemicals against oxidation. Thus, Vitamin E prevents the oxidation of unsaturated and polyunsaturated fatty acids. The need for Vitamin E is directly related to the polyunsaturated fatty acids or fish oil content of the diet since these have elevated peroxidative potential.
Research studies, in the past decade indicate that major diseases that afflict humankind worldwide may be preventable by the intake of nutrient substances, namely antioxidants. The term xe2x80x9cantioxidantxe2x80x9d nutritional agent has been applied to a number of specific nutrients, especially to Vitamin E. Antioxidant use therefore has gained popularity to prevent disease and to promote health. These compounds are readily available, nontoxic, and the usual intake varies in individuals depending on the diet.
To appreciate antioxidants, one must understand xe2x80x9cfree-radicalsxe2x80x9d, which are unstable, highly reactive oxygen molecules (ions) that circulate in the bloodstream. To become chemically stable, free-radicals snatch electrons from other molecules in the body, a process that causes cell damage (oxidative damage). Antioxidants prevent oxidative damage by donating electrons to free-radicals. As a fat-soluble vitamin, Vitamin E is amenable for entry and storage in cell membranes to absorb free-radical molecules and reduce the damage they cause.
The normal metabolic processes release some free-radicals, but our body repairs most of the oxidative damage these natural free radicals cause. However, if we flood our bloodstream with an unusually large number of free radicals, typically by smoking or by eating a high-fat diet, over time, oxidative damage can overwhelm the body""s repair mechanisms, setting us up for degenerative diseases. Antioxidants protect cells from the damage caused by free-radicals, unstable compounds that result from lifestyle factors like environmental stress and strenuous exercise, as well as natural processes like aging.
Tocotrienols, due to their unsaturated side chains, provide much stronger antioxidant effect and protect against oxidation of xe2x80x9cbadxe2x80x9d cholesterol, LDL, which, if oxidized, leads to buildup of plaques in arteries and increased risk of heart attack or stroke.
xcex1-tocotrienols have demonstrated superior antioxidant potential against iron induced lipid peroxidation in animal studies. Furthermore, tocotrienols caused regression in carotid artery stenosis or narrowing while acting as potent antioxidants in preventing coronary heart disease.
Various forms of the xcex1-tocopherols have varying activity. Until now, most active isomer was d-xcex1-tocopherol. Vitamin E supplements are stabilized and supplied as either the acetate or succinate esters.
Insufficient Vitamin E results in free-radical mediated lipid peroxidation of membranes and their destruction. Vitamin E protects the skeletal muscles, nervous system, and retina of the eye from oxidation. Vitamin E is essential for normal immune function. Vitamin E mitigates the prostaglandin driven severity of inflammation, PMS and circulatory disorders (leg cramps at night and sticky blood platelets). Vitamin E may reduce the toxicity of metals and protect against free-radical promoting environmental pollutants such as ozone, oxides of nitrogen (NOx), drugs, alcohol and smoking. Vitamin E inhibits the conversion of nitrites in smoked, barbecue, pickled and cured foods to carcinogenic nitrosamines in the body. Nearly 60% of the factors that affect health depend on lifestyle and exposure to risk factors. Aging is essentially oxidative deterioration of tissues. Since Vitamin E can prevent or slow down reactions of such oxidative damage, Vitamin E may slow the aging process. The importance of antioxidants stems from the number and breadth of diseases where they play a preventive role, such as heart disease, cancer, and eye disease. Furthermore, lack of significant toxicity in its use and the ease of use as a nutritional supplement attest to the significance Vitamin E.
Epidemiological studies suggest that low blood levels of Vitamin E are associated with increased risk of development of degenerative diseases including coronary heart disease, Alzheimer""s disease, cataracts, and certain types of cancer. Two epidemiological studies of more than 12,000 adults conducted at Harvard University found a 40% decrease in heart disease risk in subjects taking at least 100 IU of Vitamin E daily. However, people taking a higher dose of Vitamin E supplements with only xcex1-tocopherol may not be realizing full benefit. This is further substantiated by a recent study indicating that xcex3-tocopherol traps mutagenic electrophiles such as NOx and complements xcex1-tocopherol.
Oral doses of Vitamin E ranging from 50 to 400 International Units (IU) per day did not show any adverse effects in double-blind clinical studies. The recommended daily amount (RDA) is 8 to 10 mg per day for healthy adults. In the U.S., 400 IU soft gelatin capsules are the most popular dosage form of Vitamin E. To achieve the potency of a 400 IU capsule, a person needs to consume 454 g of sunflower seeds, 2.2 Kg of wheat germ or 1.9 liters of corn oil totaling 8,000 calories daily. In 1993, 33% of Vitamin E supplement users took 400 IU/day. 51% took the Vitamin E in capsule form and 26% took the tablet form of Vitamin E. The RDA of tocotrienols ranges from 25 to 60 mg.
xcex1-tocopherol is fairly stable to heat, but loses potency on exposure to air, heat and light. Similarly, tocotrienols are heat stable. If Vitamin E supplements are enclosed in a soft gelatin capsule and stored in a cool, dark place, they retain potency for at least 3 years. The esters of xcex1-tocopherol are considerably more stable in soft gelatin capsules. However, Vitamin E supplements when spray dried and stabilized by excipients also retain potency. Recent research indicates that xcex1-tocopherol and its acetate ester are equally effective in humans.
Fat-soluble vitamins, like Vitamin E, are found in foods associated with lipids and are absorbed from the intestine with dietary fats. Therefore, Vitamin E intake is recommended with a meal and normally 20 to 40% of the ingested Vitamin E is absorbed. Multiple doses instead of a single dose of Vitamin E taken daily with a meal seem to indicate increased absorption and utility in the body. In fact, a combination of tocopherols, tocotrienols and phospholipid emulsifier have been shown to be effective carrier of molecules for improved absorption. In cardiovascular clinical studies, 50 mg/day Vitamin E was used for a periods ranging from 1 to 8.2 years without any adverse effects. Vitamin E is the least toxic among the fat-soluble vitamins. No evidence of detrimental effects of Vitamin E is observed even at daily doses of 100 to 500 mg. Human studies at daily 240 mg doses of tocotrienols for 18-24 months did not indicate any adverse effects. Further animal studies show safety of tocotrienols up to 12,000 mg/day.
Reactive oxygen species are of great interest in medicine because of overwhelming evidence relating them to aging and various disease processes such as atherosclerosis, brain dysfunction, birth defects, cataracts, cancer, immune system decline, rheumatoid arthritis, and inflammatory bowel diseases. A complex antioxidant network is effective to counteract reactive oxygen species that are detrimental to human life, such as Vitamin E.
Only recently have reliable analytical methods become available to quantitatively measure the total antioxidant capacities, such as oxygen radical absorbance capacity (ORAC) assay, to evaluate the potency of antioxidant formulations. The ORAC method utilizes a peroxyl radical generator and beta-phycoerythrin protein as an indicator of oxidation by measuring the fluorescence of the protein. The ORAC values are expressed as micromoles of Trolox (6-hydroxy-2,5,7,8,-tetramethylchroman-2-carboxylic acid) equivalents per liter of the sample and Trolox shows total inhibition of the peroxyl radical action.
The ORAC assay is a widely accepted method in the world for identifying the antioxidant potential in a sample/product. The samples can be a pure compound, blood plasma, various tissues and foods such as fruits, vegetables, or dietary supplements. The total antioxidant capacity is reflected from various antioxidants present in the sample and their interactions. For example, the ORAC values of antioxidant dietary supplements varies from 10 to 4,000 micromoles per gram. The advantage of this assay is that it helps quantify the antioxidant potential value of a sample compared to other commercial samples/sources.
Several other methods have been developed to measure the total antioxidant capacity of a sample. However, the peroxyl or hydroxyl radicals used in the ORAC assay as pro-oxidants make it different and unique from the other assays that involve oxidants that are not necessarily pro-oxidants. Further, substantial deficiencies of other methods have been overcome in the ORAC assay. For example, the ORAC assay was compared to other assays and the ORAC assay seems to provide a better correlation to the antioxidant capacity. Therefore, the ORAC assay method provides a valuable tool with which a researcher can quickly determine the value of a particular formulation, where increased potency and reduced cost are desired. The present full spectrum Vitamin E formulation delivers at least 17 times the antioxidant capacity of synthetic Vitamin E and twice the antioxidant capacity of natural Vitamin E.
Recent research has increased the popularity of the therapeutic and prophylactic advantages of Vitamin E and its antioxidant effects. Soft gel encapsulation of Vitamin E is safe and protects the potency of the ingredients and ensures a consistent level of active ingredients. Soft gels are easy to swallow and mask any unpleasant taste or odor associated with some of the ingredients. Soft gel capsules dissolve quickly and provide for rapid absorption of the active ingredients and soft gels do not need the fillers and binders used in most tablets and powders, although pigments are sometimes used for cosmetic value.
Vitamin E can be provided in other forms, such as tablets and powders, where the active ingredients (which are oils) are placed on the surface of a carrier such as starch or maltodextrin. However, the present invention can be provided in any of the common dosage or delivery forms.
The present invention comprises stable and nontoxic formulations of natural and synthetic Vitamin E, mixed tocopherols, and tocotrienols. Such formulations improve the antioxidant capacity of a given dosage over and above that of natural and synthetic Vitamin E formulations as measured by ORAC assays. A preferred soft gel formulation includes synthetic Vitamin E, natural Vitamin E, mixed tocopherols, tocotrienols and soybean oil as an economical non-interacting carrier for administration once a day. Tocotrienols are related to Vitamin E. Palm and rice are rich and natural sources of the tocotrienols used in the formulation, but cost effective synthetic tocotrienols may be available in the future. Tocotrienols by themselves can not replace Vitamin E, but with their individual potency and distinct protective roles, they complement Vitamin E. Hence, the potent blend of Vitamin E, tocopherols and tocotrienols in the present formulation provide optimal synergy.
It is therefore an object of the present invention to provide improved formulations of a full complement of Vitamin E isomers including tocotrienols, which produce a significantly synergistic antioxidant capacity of the formulations that is greater than in heretofore known formulations or delivery systems.
It is another object of the present invention to provide Vitamin E formulations, which have surprisingly large antioxidant capacities, and can be provided in any dosage or delivery forms compatible with ordinary Vitamin E formulations, such as soft gel, tablet, powder, suppository, micellar, and injectable forms, or any other delivery systems and can provide such beneficial antioxidant to living beings, whether human or other animals.
It is another object of the present invention to provide a reduced cost soft gel formulations of full spectrum Vitamin E, with an enhanced antioxidant capacity as shown by ORAC assays.